Typewriter ribbon spool having congruent halves formed of plastic and metal

ABSTRACT

An ink ribbon spool for type-writing machines is disclosed, assembled from two congruent parts. Each part comprises an essentially cylindrical hub portion made of plastics and a metal, disc-like flange anchored to the hub portion by dove-tailed projections directed inward and embedded in the plastics material of the hub. The two spool halves are connected by pins and recesses acting like a snap fastener. The spool disclosed is adaptable to spool drive mechanisms having different dimensions. Universality is achieved by elastic lug-elements integrally attached to the interior wall of the hub portion and serving to center the spool on the driving axle. Preferably a metal strip having the form of a double-headed arrow is inserted between the spool halves and serves as a hook for fastening the end of the ink ribbon.

United States Patent Gely [ 1 Sept. 30, 1975 TYPEWRITER RIBBON SPOOLHAVING CONGRUENT HALVES FORMED OF PLASTIC AND METAL [75] Inventor:Michel Albert Gely, Luzancy,

France [73] Assignee: Kores Holding Zug AG, Zug, Switzerland [22] Filed:July 3,1973

[21] Appl. No.: 376,158

[30] Foreign Application Priority Data July 31. 1972 Austria 6572/72[52] US. Cl. 197/175; 242/71.8; 242/74 [51] Int. Cl." B41J 35/00 [58]Field of Search 197/175; 242/71.8, 71.8 A,

[56] References Cited UNITED STATES PATENTS 2.203.101 6/1940 Pausin242/7l.8 A

2,667,257 l/l954 Hurtado 197/175 2146,6192 5/1956 WljChlTlillL. 242/71.8A 2 042.180 7/1962 Bishop 197/175 3.051.287 8/1962 Grafton 197/1753.065.838 11/1962 Biedinger et 197/175 3,145,823 8/1964 Spradlin 197/1753.327.960 6/1967 Hedin 242/718 A 3,438.592 4/1969 Posso 242/71.8 A3.512.734 5/1970 Priest 242/7l.8 X

FOREIGN PATENTS OR APPLICATIONS 63,440 4/1955 France 242/718 703,7412/1954 United Kingdom... 242/71.8 497.826 9/1954 Italy t. 242/718 OTHERPUBLICATIONS IBM Technical Disclosure Bulletin, Web Spool, D. S. Proper,Vol. 14, N0. 8, January 1972, p. 2258.

Primary Examiner-Ernest T. Wright, Jr. Attorney, Agent, or Firm-Holman &Stern [57] ABSTRACT An ink ribbon spool for type-writing machines isdisclosed, assembled from two congruent parts. Each part comprises anessentially cylindrical hub portion made of plastics and a metal,disc-like flange anchored to the hub portion by dove-tailed projectionsdirected inward and embedded in the plastics material of the hub. Thetwo spool halves are connected by pins and recesses acting like a snapfastener. The spool disclosed is adaptable to spool drive mechanismshaving different dimensions. Universality is achieved by elasticlug-elements integrally attached to the interior wall of the hub portionand serving to center the spool on the driving axle. Preferably a metalstrip having the form of a double-headed arrow is inserted between thespool halves and serves as a hook for fastening the end of the inkribbon.

4 Claims, 4 Drawing Figures Sept. 30,1975 Sheet 1 of 2 3,908,819

US. Patent US. Patent Sept. 30,1975 Sheet 2 of2 3,908,819

F'IG.2

m m E 1 z 1 .w I I 4 ml J n f w TYPEWRITER RIBBON sPooL HAVI G;

CONGRUENT HALVES FORMED or PLASTIC AND METAL BACKGROUND OF THE INVENTIONThis invention relat es to an i nk ribbon for typewrite rs. Most of suchrib bon spools are still m ade from sheet metal and comprise a hub made.from sheet metal rolled substantially. to acylinder whichhub isconnected tostwo disc-like flanges servingto guide theribbon'l'aterally.In most cases, the flanges are connected to the hubby seaming or foldingover or by lugs formed on one part and inserted through slots in theother part which lugs are then bent over. Numerous operations arerequired in the manufacture of such sheet metal parts.

Attempts had been made and are still beingmade tci manufacture suchribbon spools from plastics material,

embodiments assembled from a plurality of separately made parts. In thelatter case, a plurality of different molding tools had to beprovidedfor making the several parts. Thus the costs of manufactureof suchspools had been considerably increased. v

SUMMARY OF THE INVENTION It is an object of the invention toavOid thedisadvantages described above. This is accomplished. according to theinvention in that thespool ,isassembled from two spool halves eachhaving a hub portion and a flange, each of the halves having congruentform, the shell of each hub portion extending tothe-mid-li'ne of the inkribbon to be wound onto the spool'andinfthateach hub portion is madefrom plastics materialand'the-flange is made from sheet metal, beingembedded into the hub portion by molding.

According to another feature of the invention, each flange comprisesdovetail-shaped projections directed .radially inward for being embeddedin and anchored to the hub portion. According to another feature of theinvention for connecting the spool halves each hub por tion is providedwith at least one pin arranged parallel to the spool axis and protrudingover the partition face between the spool halves and with correspondingrevcesses equal in number to that of the pins, the pins and the recessesbeing arranged eccentric to the spool axis. Preferably, each hub portionis provided with a slot parallel and eccentric to the spool axis intowhich a strip of sheet metal is insertable, the strip of sheet metalhaving the shape of a double arrow whose arrow-heads iprotrude over theshell of the hub portion and serve to fasten the end of the ink ribbon,and wherein additionally each hub portion adjacent to the slot isprovided with a recess arranged parallel to the spool axis into each ofwhich recesses a sleeve is insertable, the sleeves being integrallyattached to the sheet metal strip and consisting of rolled lateralprojections thereof.

inner oescjkibrrofi o f 'I'iE DRAWING A'number of furtherdesirablefeatures of the invention will-be explained with reference to thedrawing, in

hich;

FIG. 1-'is a-top plan view showing onespool half as two halves, one'ofwhich is shown in 'a sectiontaken L along "line"2'-2 in FIG. 1, 4 i FIG.3-shows a metal strip which has the shape FIG. 4 showsthe metal strip inangles to FIG: 3. c v

bEscRiPTIoN OF THE PREFERRED Y 1 EMBODIMENTS The spool 1 consists of twoidentical spool halves 1d andlb. Each spool half l'a, lb consists of acylindrical f hub-portion 2 (a'or'b) of plastics material and a disclikeflange 3 (a or b) of sheet metal. The flange 3 is held a in the hubportion 2 by means of dovetail-shaped 'pr'ojectio ns 23 protruding"radially inward, which projec tions 23 are embedded in the hub portion2 by molding. Hereinafter, where it appears necessary for the sake ofclearriess, reference characters are provided with the suffixes a or bto indicate that the designated component belongs to a specific spoolhalf la, lb for instance,

the left h and spool half 1a in FIG. 2", or the other spool half, suchas theright-hand spool half lbiAttention is directed to the fact thatthere is" basically no difference between components having referencecharacters which differ by the suffixes a and'b only, and thatsuchcomponents are identical or congruent components of cong'ruentjspoolhalves 121, lb. s

Each hub portion 2 consists of an e ndw all and an approximatelycylindrical casing 9'. The height of the cylinder is approximately onehalf of the width of the ink ribbonj The end wall 2( l'jis provided withradially elongated apertures 21, which at the centerof the end;

wall 20 merge into a circular aperture 24 and together" with the latterform a coupling star, which is adapted to receive the axis of a spoolholder and one or more coupling of a spool drivej This spool drive isnot shown in the drawing. i

From the inner surface of the cylindrical casing 9 of the hub portion 2made of plastic spring lugs 22 which are integrally molded to the casing9 extend first radially inward and are angled in the same direction eachwhere they are adjacent to the circular aperture 24. In their radialportion, these spring lugs 22 in part are firmly connected to the endwall 20. Just as the apertures 21, spring lugs 22 are arranged in acentrally symmetrical pattern. They serve to center the spool l on thespool axle. The cylindrical casing 9 of the hub portion 2 is increasedin thickness at two diametrically opposite sections. One of thethickened portions has a preferably oval recess 5 arranged parallel tothe axis of the spool 1, and beside said recess 5 hasa pin 4, which isalso parallel to the axis of the spool l and protrudes over the jointingplane of the hub portion 2. The pins 4 and recesses 5 of two identicalspool halves 1a, lb are so designed that each pin 4a can be insertedinto a recess 5b and each pin 4b can be inserted into a recess 5a so asto form a permanent joint. The recesses 5a, 5b may be slightly undercutand the pins 4 may be somewhat thickened at their tip so that a joint isobtained a double'arrow and-is? provided -with fixing hooksqandf anelevation at right? similar to that of a snap fastener. Pins 4 andrecesses 5 are arranged eccentric to the axisof spool 1. I

The recesses 5 do not extend through the entirehub portion 2 but extendonly to a point adjacent to the end wall 20. The connecting pins 4 arecorrespondingly shorter. To enable air to escape from the recesses 5 asthe pins 4 are forced into the same, the recess 5 is continued by aventing opening 25 in the end wall '20.

The other, thickened portion of the hub casing 9, diametrically oppositeto the connecting pins 4 and. recesses 5 has a slot 6 (a or b) whichextends along a chord of the circle representing the cylindrical casing9, which slot 6 intersects the thickened portion of the'hub portion 2approximately parallel to the spool axis. In each spool half la, lb twocylindrical recesses or apertures 10, 11(a or b) approximatelytangentially adjoin said slot 6. A metal strip 7 having the shape ofadouble arrow and provided with arrow-heads 8 can be inserted into theslot 6 so that the arrow-heads 8 protrude over the periphery or casing 9of the hub portion 2 of the spool l. The two arrow-heads 8 are angularlybent toward the hub portion 2 of the spool 1 to form a fixing hook towhich the end of the ink ribbon is secured. In a preferred embodiment ofthe metal strip 7, two punched projections are provided on each side,which projections are equally spaced from the middle of the double arrowand which during manufacture of the double arrow are rolled to formsleeve portions (12, 13, 14, 15) insertable into the apertures 10 a, band 11 a, b. Because the apertures 10 and 11 are symmetrical withreference to the same plane of symmetry as the connecting pin 4 and thecorresponding recess 5, the sleeve portions 12, 13, 14 and 15 of themetal strip 7 can be inserted simultaneously into the apertures 10a, 1lb'and 11a, 10b so as to contribute to a permanent connection of the twospool halves 1a and 1b The spool 1 shown and described can be made atvery low cost as a mass-produced article. A single mold is sufficient tomake the spool halves la and lb. The flange 3 made of sheet metal isinserted into the mold, which is then closed, and plastics material isinjected into the mold to make the hub portion 2. A metal strip 7 isinserted into two spool halves 1a, lb and the hub portions 2 of thelatter are superimposed so that each pin 4 can enter an opposite recess5 of the other'hub portion 2. After the two hub portions 2 have beenforced together, the spool 1 is ready to receive a ribbon.

I claim:

1. In an ink ribbon spool comprising two spool halves, each spool halfincluding a hub portion and a flange, wherein the two spool halves havecongruent form, a casing of each hub portion extending to a midline ofanink ribbon to be wound onto the spool, each hub portion being madefrom plastic material, the improvement' wherein each flange is made ofsheet metal and has dovetail shaped projections directed radially inwardfor being embedded in and anchored to the hub portion; each hub portionbeing provided with at least one pin arranged parallel to the spool axisand protruding over the jointing plane of the spool halves, and withfirst recesses corresponding to the pins and equal in number; the pinsand the first recesses being arranged eccentrically to an axis of thespool; and the spool halves being connected at the hub portions byfitting the pins into the first recesses.

2. An ink ribbon spool according to claim 1, wherein each hub portion isprovided with a slot parallel and eccentric to the spool axis and intowhich a strip of sheet metal is inserted, the strip of sheet metalhaving the shape of a double arrow having arrowheads which protrude overthe casing of the hub portion and serve to fasten an end of the inkribbon, a plurality of sleeves integrally attached to the sheet metalstrip and consisting of rolled lateral projections thereof and whereinadditionally each hub portion adjacent to the slot is provided with afurther recess arranged parallel to the spool axis into each of whichfurther recesses a respective sleeve is insertable.

3. An ink ribbon spool according to claim 2, wherein each hub portionhas two of the first recesses positioned symmetrically'with reference toa plane of symmetry governing the positions of said pins and first re-,cesses.

4. An ink ribbon spool according to claim 1, wherein each hub portionhas two of the first recesses positioned symmetrically with reference toa plane of symmetry governing the positions of said pins and firstrecesses.

1. In an ink ribbon spool comprising two spool halves, each spool halfincluding a hub portion and a flange, wherein the two spool halves havecongruent form, a casing of each hub portion extending to a mid-line ofan ink ribbon to be wound onto the spool, each hub portion being madefrom plastic material, the improvement wherein each flange is made ofsheet metal and has dovetail shaped projections directed radially inwardfor being embedded in and anchored to the hub portion; each hub portionbeing provided with at least one pin arranged parallel to the spool axisand protruding over the jointing plane of the spool halves, and withfirst recesses corresponding to the pins and equal in number; the pinsand the first recesses being arranged eccentrically to an axis of thespool; and the spool halves being connected at the hub portions byfitting the pins into the first recesses.
 2. An ink ribbon spoolaccording to claim 1, wherein each hub portion is provided with a slotparallel and eccentric To the spool axis and into which a strip of sheetmetal is inserted, the strip of sheet metal having the shape of a doublearrow having arrowheads which protrude over the casing of the hubportion and serve to fasten an end of the ink ribbon, a plurality ofsleeves integrally attached to the sheet metal strip and consisting ofrolled lateral projections thereof and wherein additionally each hubportion adjacent to the slot is provided with a further recess arrangedparallel to the spool axis into each of which further recesses arespective sleeve is insertable.
 3. An ink ribbon spool according toclaim 2, wherein each hub portion has two of the first recessespositioned symmetrically with reference to a plane of symmetry governingthe positions of said pins and first recesses.
 4. An ink ribbon spoolaccording to claim 1, wherein each hub portion has two of the firstrecesses positioned symmetrically with reference to a plane of symmetrygoverning the positions of said pins and first recesses.